1. Field of the Invention
The present invention relates to a wireless power transmission control method in a wireless power transmission system, a wireless power transmission apparatus using the same, and a wireless power receiving apparatus using the same.
2. Description of the Related Art
Generally, a battery pack is charged with electrical energy supplied from an external charger and supplies the charged energy to power the operation of portable terminals (mobile phones, PDAs, and the like). The battery pack generally comprises a battery cell which can be charged with electrical energy, a circuit for charging and discharging the battery cell (the discharging being to supply its electrical energy to a portable terminal, and the like.
To electrically connect a charger and a battery pack and thus allow charging of the battery pack, one known method is a terminal supply method, wherein a terminal of the charger through which the power is outputted is directly connected to a terminal of the battery pack to which the power is inputted through a cable, a connector, or the like.
However, when the terminal supply method supplies electrical energy, since the terminal of the battery pack and the terminal of the charger have different potential differences, the terminal supply method may cause an instantaneous discharging phenomenon when the charger and the battery pack contact or separate from each other. When foreign materials have accumulated in one or both terminals, the instantaneous discharge phenomenon may heat said materials, triggering a fire or the like.
Further, the electrical energy charged in the battery pack may be naturally discharged into the environment through the terminal of the battery pack, due to humidity or the like, which may lead to a degradation in lifespan and performance of the battery pack.
Recently, in order to solve the above problems, a contactless charging system using a wireless power transmission method and control methods has been proposed.